scsi: ufs: set load before setting voltage in regulators

This sequence change is required to avoid dips in voltage during boot-up.

Apparently, this dip is caused because in the original sequence, the
regulators are initialized in lpm mode.  And then when the load is set to
high, and more current is drawn, than is allowed in lpm, the dip is seen.

Link: https://lore.kernel.org/r/1581392451-28743-3-git-send-email-cang@codeaurora.org
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index bae0a406ab7ce3742d13ebeda649a26fddf9b8cf..9c39fae99b61abc86ed12e052619aaf794c6d838 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -7249,6 +7249,11 @@ static int ufshcd_config_vreg(struct device *dev,
        name = vreg->name;
 
        if (regulator_count_voltages(reg) > 0) {
+               uA_load = on ? vreg->max_uA : 0;
+               ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
+               if (ret)
+                       goto out;
+
                if (vreg->min_uV && vreg->max_uV) {
                        min_uV = on ? vreg->min_uV : 0;
                        ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);
@@ -7259,11 +7264,6 @@ static int ufshcd_config_vreg(struct device *dev,
                                goto out;
                        }
                }
-
-               uA_load = on ? vreg->max_uA : 0;
-               ret = ufshcd_config_vreg_load(dev, vreg, uA_load);
-               if (ret)
-                       goto out;
        }
 out:
        return ret;